Is there a charge for calling 400-666-8800 by mobile phone?

There may be a charge for dialing 400-666-8800, and the specific charging items and charging standards vary according to regions and operators.

Usually the number starting with 400 is a long-distance number, and operators in different regions may charge according to the call duration and tariff standard. The specific fee may vary due to factors such as mobile phone package, dialing method and call duration.

If you want to know the specific cost information, I suggest you consult your local operator or customer service hotline.